Hydroentangled web with ultrafine fibers

ABSTRACT

A hydroentangled nonwoven fibrous composition, comprising as a hydroentangled web from 60 to 90% by weight of defibrated or refined natural cellulose fibers; and from 10 to 40% by weight of manmade sustainable fibers and a method to prepare the fibrous composition is provided. The nonwoven fibrous hydroentangled web comprises no binder, adhesive or thermal bonding fiber and has sufficient wet strength to be usable as a wipe and water dispersibility to be suitable as a flushable product for disposal in a municipal sewer system. A disposable wipe containing the hydroentangled nonwoven fibrous composition is also provided.

FIELD OF THE INVENTION

This invention is directed to a disposable nonwoven web composition having sufficient wet strength to be useful as a consumer wipe product while having rapid dispersibility in an aqueous medium such as sewer or septic system and a continuous method for preparing the disposable nonwoven webs which employs a minimal number of operations. The nonwoven web based wipe is economical to produce, is constructed of manmade sustainable and naturally derived raw materials and contains no synthetic binders or thermoplastic resins. Wipes prepared with the disposable nonwoven web of the embodiments of this invention are advantageous for having good wet strength and rapid water dispersibility thus avoiding clogging of sewer systems, requiring less wear and stress on municipal sewer pumps and displaying rapid biodegradation in standard sewage systems.

BACKGROUND OF THE INVENTION

Disposable nonwoven substrates are employed for the production of a wide variety of consumer products which are generally used once and discarded. Such products include disposable cleansing wipes, disposable diapers, disposable adult incontinence products, disposable pads typically employed in hospitals for absorption of body fluids and cosmetic applicators or cosmetic pads for removal of make-up and other materials from a keratinous substrate.

Such commercial products constitute an industry having ever increasing growth potential and expansion of utility. However, as virtually all such products potentially enter the environment through landfill or sewage systems, there is a need for a disposable nonwoven material that is simple to produce, contains minimal or no amount of chemical components that have poor biodegradability such as binders, adhesives or thermoplastic polymers and yet has good wet tensile strength as required for performance. In addition, a product is sought which is constructed to have minimal lint content and meets codes for categorizing as a flushable article acceptable for municipal and private sewage systems. Additionally, the material should be economical to produce.

To date the properties of high wet strength and rapid dispersibility have been considered opposing characteristics wherein increased wet strength is obtained at the loss of water dispersibility and vice versa. Formulation of products such as disposable wipes has generally required a trade-off such that an optimum acceptable combination of wet strength and dispersibility are obtained, rather than a combination of optimal wet strength and optimal water dispersibility.

Conventionally, nonwoven disposable wipe products can be produced via one of two basic technologies known in the industry as “airlace” and “hydraspun” processes. Different producers may conduct these technologies with variation based on intended end use and available production equipment but the basic principles of operation are retained.

Airlace methods combine the operations of depositing an airlaid web of staple length fibers and wood pulp fibers onto a nonwoven carrier layer or precursor base nonwoven web and hydroentangling the airlaid layer with the nonwoven carrier. This technology is described in U.S. Pat. No. 8,250,719 to Ouellette and the references described therein. In addition to employing a carrier web, Ouellette describes bonding the airlaid fibers with hot air or a spray adhesive.

According to the “hydraspun” method as described in U.S. Pat. No. 4,755,421 to Manning et al. a wetlaid web of pulp and manmade fibers is hydroentangled and dried. However, U.S. Pat. No. 5,292,581 to Viazmensky et al. indicates that such products suffer from poor wet strength and describe that the addition of binders substantially improves the strength. More recently, U.S. Pat. No. 7,732,357 to Annis et al. describes the use of binder fibers to the nonwoven sheet that upon heating become activated by at least partial melting and form fiber to fiber bonds. The binder fibers contain polyethylene, polypropylene, polyethylene terephthalate and mixtures thereof.

A method to prepare a nonwoven web through a continuous process involving air layering of a homogeneous mixture of natural cellulose fibers and staple fibers followed by hydroentangling is described in U.S. application Ser. No. 13/943,146, filed Jul. 16, 2013, now U.S. Pat. No. 9,394,637. Further, the hydroentangled airlaid web and products thereof are described in U.S. application Ser. No. 15/099,911. Even though the hydroentangled nonwoven webs described in these applications provide flushable products having utility in conventional markets as described above, there remains a need for an economical nonwoven composition based on sustainable raw materials having combined optimized wet strength and optimized water dispersibility while containing no adhesive, binder or binder fibers, which is also acceptable as a flushable product for municipal sewer and private septic systems. Further, there is a need for an economical and energy efficient method to produce such nonwoven material that is continuous and manufactures a constant high quality product.

SUMMARY OF THE INVENTION

Thus, an objective of the present invention is to provide a nonwoven web product, containing biodegradable and sustainable raw materials, which is free of adhesives, binders and binding fibers, yet has high wet strength as required for performance such as a wipe combined with rapid water dispersibility to he suitable as a flushable product for disposal in sewer and/or septic systems.

A further objective is to provide a method to produce the nonwoven web product having minimal processing operations, wherein the high wet strength may be obtained without inclusion of adhesives, binders or binding fibers in the nonwoven web.

These and other objectives have been achieved according to the present invention, the first embodiment of which includes a nonwoven fibrous composition, comprising as a hydroentangled web: from 60 to 90% by weight of defibrated or refined natural cellulose fibers; and from 10 to 40% by weight of manmade sustainable fibers; wherein the nonwoven fibrous hydroentangled web comprises no binder, adhesive or thermal bonding fiber, a fiber length of the defrbrated or refined natural cellulose fibers is less than or equal to 3.5 mm, a fiber length of the manmade sustainable fibers is from 6.0 to 12.0 mm, a denier of the sustainable fibers is 1.0 dpf or less, a basis weight of the nonwoven web is from 20 g/m² to 100 g/m², and a thickness of the nonwoven web is from 0.25 mm to 2 mm.

In an aspect of the first embodiment, the CD wet strength of the nonwoven fibrous composition may be at least 5N/5 cm. In a further aspect a Slosh Box dispersibility time of the nonwoven fibrous composition may be 15 minutes or less. In a preferred aspect the CD wet strength of the nonwoven fibrous composition is at least 5N/5 cm and the Slosh Box dispersibility time of the nonwoven fibrous composition may be 15 minutes or less.

In another embodiment, the present invention provides a method for production of the nonwoven fibrous composition comprising: preparing a homogeneous web containing from 60 to 90% by weight of defibrated or refined natural cellulose fibers and from 10 to 40% by weight of manmade sustainable fibers; wherein the homogeneous web comprises no binder, no adhesive and no thermal bonding fiber; hydroentangling the homogeneous web to consolidate the web on at least one side; and drying the hydroentangled web to obtain the nonwoven fibrous composition; wherein a fiber length of the defrbrated or refined natural cellulose fibers is less than or equal to 3.5 mm, a fiber length of the manmade sustainable fibers is from 6.0 to 12.0 mm and a denier of the manmade sustainable fibers is 1.0 dpf or less.

In one aspect of the second embodiment, the homogeneous web containing the defibrated natural cellulose fibers and the manmade sustainable fibers may be an airlaid web directly formed on a carrier of an airformer without preforming a precursor web or incorporating a continuous filament web.

In another aspect of the second embodiment the homogeneous web containing the refined natural cellulose fibers and the manmade sustainable fibers may be a wetlaid web.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic drawing of an arrangement of water jets in a hydroentanglement unit according to one embodiment of the invention.

FIG. 2 shows a schematic diagram of a continuous production line including airlayering to prepare the homogeneous web to be hydroentangled according to one embodiment of the invention.

FIG. 3 shows comparative data for dispersible nonwoven webs according to the invention and selected commercially available wipes.

DETAILED DESCRIPTION OF THE INVENTION

According to the following description, all numerical ranges described include all sub-ranges and all values there between unless otherwise specified. All weight content values are based on total weight. The following description provides a general description of the present invention and specific preferred embodiments. However, one of ordinary skill will recognize that many variations of the invention may be possible without departing from the gist of the invention. This description and the following Claims are intended to include all such variation.

In a first embodiment, the present invention provides a nonwoven fibrous composition, comprising as a hydroentangled web: from 60 to 90% by weight of defibrated or refined natural cellulose fibers; and from 10 to 40% by weight of manmade sustainable fibers; wherein the nonwoven fibrous hydroentangled web comprises no binder, adhesive or thermal bonding fiber, a fiber length of the defribrated or refined natural cellulose fibers is less than or equal to 3.5 mm, a fiber length of the manmade sustainable fibers is from 6.0 to 12.0 mm, a denier of the manmade sustainable fibers is 1.0 dpf or less, a basis weight of the nonwoven web is from 20 g/m² to 100 g/m², and a thickness of the nonwoven web is from 0.25 mm to 2 mm.

According to the present invention manmade sustainable fibers are materials which are polymeric renewable products obtained from wood, field crop fibers or from other agricultural sources. The manmade sustainable materials are distinguished from synthetic polymers which are ultimately based on oil derived raw materials. Examples of synthetic polymers include, but are not limited to, vinyl polymers such as polyethylene, polypropylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, nylons, polycarbonates and polysulfones. In contrast, manmade sustainable materials according to the embodiments of the present invention may generally be derived from base raw materials obtained from renewable sources such as a rotational crop or an animal produced material. The base raw material may be modified as in the case of cellulose acetate. Examples of sustainable fiber materials include but are not limited to cellulose acetate, polylactic acid, esters of polylactic acid, amities of polylactic acid, lyocell, viscose and milk protein.

The length of the defribrated or refined natural cellulose fibers is no more than 3.5 mm, preferably 1.5 mm to 3.5 mm, most preferably 2.5 to 3.5 mm. Any natural cellulose fiber may be employed as the short fiber of the mixture. In one embodiment a wood pulp of the described length may be the short fiber and in a preferred embodiment, a southern pine Kraft may be the natural cellulose fiber. Wood pulp obtained from a sulfite pulping process may additionally be the source of the natural cellulose fibers. Mixtures of natural cellulose fibers may be used.

The content of the defribrated or refined natural cellulose fibers may preferably be from 70 to 90% by weight of the total fiber content and most preferably from 80 to 85% by weight. The performance properties of the hydroentangled web may be modified by variation of the content of the defribrated or refined natural cellulose fibers and one of skill in the art will recognize that the composition content within the described ranges may be varied depending on the source and history of the defribrated or refined natural cellulose fibers.

Defibrated fibers are wood fibers obtained in a dry hammermill type operation which is known to one of skill in the art. In the hammermill treatment the wood pulp is defribrated into individual fibers which are airborne and dispersed in the air flow which carries the dry individual fibers to an airlayering operation. Good dispersion and effective deagglomeration of the pulp may be important to the formation of an air-laid web.

The refining process is applied to wet laid wood pulp fibers. Unlike the defibration process, in a refining process the pulp is dispersed in an aqueous mixture and then exposed to mechanical compression and shearing which results in internal delamination and splitting of the fiber agglomerates. The degree of refining is related to the mechanical energy or intensity imparted to the pulp during refining and in addition to delamination, the refining process may increase the flexibility of the fibers and may also collapse the fibers into a ribbon shape which may be useful to increase available fiber contact surface and thus provide opportunity for increased bonding strength and nonwoven mat density. Further, the refining process may straighten kinked and/or bent fibers and thus increase the effective length of the fiber. Each of these effects may be varied depending on the type of wood pulp and intensity of the refining operation. One of ordinary skill may thus engineer the refining method depending on the type of pulp and desired final properties.

The refining process may also be applied to the manmade sustainable fibers and the considerations described above may be similarly important.

However, if the intensity of the refining process is such that the tensile strength of the fibers is exceeded, fibers may be cut or broken leading to loss of any of bonding strength, water absorbency and fiber strength. Generally conducting the refining at lower intensity provides refined fibers of greater bonding strength.

The manmade sustainable fibers may be no less than 6.0 mm in length, preferably 6.0 to 12.0 mm, most preferably 6.0 mm to 10 mm. In one aspect the manmade sustainable fibers may be any of regenerated cellulosic fibers and in particular aspects a viscose or a lyocell may be employed. Mixtures of viscose and lyocell may also be employed.

The denier of the manmade sustainable fiber may be no greater than 1.0 dpf, preferably 0.6 to 1.0 dpf and most preferably 0.7 to 0.9 dpf. As understood by one of skill in the art the denier is a measure representing the finenessss of the fiber. Conventionally, fibers having a denier of 1.2 to 3.0 dpf are employed because ultrafine denier fibers having a denier of 1.0 dpf or less present significant difficulties in handling and incorporation in a nonwoven web especially in a manufacturing environment. The fibers may be highly prone to dust formation and if not handled in systems designed for such materials may present hygiene and possibly health problems. Further, when the ultrafine fibers are conveyed by air and/or water they are prone to become entangled into clumps which then makes the formation of a homogeneous web mixture with the defribrated natural cellulose fibers very difficult.

In one embodiment the manmade sustainable fibers may be regenerated cellulosic fibers and may have any of the cross sectional shapes as known to one of skill in the art. For example, conventionally known cross sectional shapes may include circular, flat, trilobal and X shaped, each may have differing degrees of crenelation or surface irregularity or waviness. As understood by one of skill in the art, the cross-sectional shape may be selected for degree of stiffness, surface area available for bonding and degree of water absorbency. Fibers marketed under the tradenames DANUFIL®, VILOFT® and GALAXY® by Kelheim Fibres are examples of commercially available viscose fibers which provide differing cross-sectional shapes and crenelation.

The content of the ultrafine denier regenerated cellulosic fibers may preferably be from 10 to 30% by weight and most preferably from 15 to 20% by weight. As described for the content of the defribrated or refined natural cellulose fibers, the content of the regenerated cellulosic fiber may be varied to obtain targeted performance properties of the nonwoven web.

The present inventors have instituted handling systems capable of eliminating the problems with the ultrafine denier regenerated cellulosic fibers described above and have unexpectedly and surprisingly discovered that when a homogeneous web of the ultrafine denier regenerated cellulosic fibers and the defribrated natural cellulose fibers as described above is hydroentangled as described herein a uniform nonwoven fibrous web may be obtained which simultaneously exhibits both high CD wet strength and rapid water dispersibility without the trade-off sacrifice described above for conventional systems.

In a preferred aspect of this embodiment the composition may contain 80 to 85% by weight of the defribrated or refined natural cellulose fibers and 15 to 20% by weight of the ultrafine denier sustainable fibers. Blend ratios of conventional commercial products are typically of the order 60-70% woodpulp and 30-40% regenerated cellulose. The mixture of the embodiments described herein may thus contains a greater proportion of the natural cellulose fibers than conventionally employed and this ratio wherein the natural cellulose fibers are in defribrated or refined form may also contribute to the highly desirable performance of the uniform fibrous web.

The basis weight of the hydroentangled nonwoven fibrous web may be from 20 g/m² to 100 g/m², preferably, 50 g/m² to 80 g/m² and most preferably, from 60 to 70 g/m² for a nonwoven web of from 0.25 mm to 2 mm in thickness. However, other embodiments within the broad range are included depending on source, history and structure of the cellulosic fibers and the sustainable fibers as described above. Further, if multiple airlaid webs are stacked, the basis weight and thickness may not he in these ranges. Basis weight may be varied by control of the process variables in the manufacturing operations described below and by other process variables conventionally known to one of skill in the present technology.

The nonwoven webs according to the present invention have strength profiles which are more omnidirectional than some conventionally available nonwoven webs. The ratio of the wet tensile strength in the machine direction (MD) to the cross machine direction (CD) is less than 3. The nonwoven fibrous composition of the first embodiment may have a CD wet strength of at least 5N/5 cm, preferably, from 5N/5 cm to 9N/5 cm. Such property is especially surprising because a CD wet tensile strength is known to be difficult to obtain in products that meet standard guidelines for flushablity.

Generally, for a product to be considered flushable it must i) clear toilets and properly maintained drainage pipe systems; ii) pass through wastewater conveyance systems and be compatible with wastewater treatment, reuse and disposal systems without causing system blockage, clogging or other operational problems; and iii) be unrecognizable in effluent leaving the wastewater treatment systems. Rapid break-up, dispersibility or disintegration in the waste water is an important requirement of a flushable product which may be conventionally measured in a Slosh Box Test.

The Slosh Box dispersibility as described herein is a test system which consists of an oscillating box containing 2.0 liters of tap water or wastewater, in which a sample of the nonwoven material is incubated for sufficient time such that the dispersed material will completely pass through a 12.5 mm perforated plate sieve. This system and test are generally known in the art.

The nonwoven fibrous composition of the first embodiment may have a Slosh Box dispersibility time of 15 minutes or less, preferably, less than 12 minutes. As indicated by the comparative test results in FIG. 3, the hydroentangled nonwoven webs according to the present invention having regenerated cellulosic fiber of denier less than 1.0 dpf have significantly shorter break-up times than nonwoven hydroentangled webs containing regenerated cellulosic fiber of denier greater than 1.0 dpf. As previously described, this performance improvement discovery was unexpected in view of conventional practice to employ fibers of greater denier.

According to the embodiments described in this application a hydroentangled uniform web having a basis weight of 60 to 70 g/m² may have a CD wet strength of from 5N/5 cm to 8N/5 cm and a Slosh Box dispersibility time of less than 12 minutes.

According to embodiments of this application the nonwoven web may be obtained by hydroentanglement of a uniform or homogeneous web of the defribrated or refined natural cellulose fibers and regenerated cellulosic fibers in the proportions previously described. This uniform or homogeneous web may be referenced as the mat to indicate the precursor web to the hydroentanglement treatment.

To form the hydroentangled nonwoven web the mat is passed into a hydroentanglement unit or spunlacing unit, wherein the mat is struck with a series of high pressure water jets to mechanically entangle or consolidate the defribrated natural cellulose fibers and regenerated cellulosic fiber and form the nonwoven web. The jets may be oriented perpendicular to the surface of the carrier or angled to provide unique properties to the web. Jets may be placed to consolidate the web from one side, preferably, the top side or from both the top and bottom side. The pressure of the jets may be from 0.04 bars/kg/h/m to 15 bars/kg/h/m, preferably, 0.1 bars/kg/h/m to 10 bars/kg/h/m, and most preferably 0.3 bars/kg/h/m to 4 bars/kg/h/m.

An embodiment showing an arrangement of jets to consolidate a web from both sides is shown schematically in FIG. 1. As indicated by FIG. 1, the formed mat may be passed along a series of carrier belts and exposed to high pressure jets indicated in numerical order. Jets 11, 12 and 13 impinge the top of the web while jets 21 and 22 strike the opposite or bottom side. The schematic jets 11-13, 21-22, 31-33, 41-43 and 51-52 represent banks of jets across the width of the web and the jet banks may be positioned and arranged to impart varying completeness of entanglement across the web. Thus the entanglement may be patterned or random depending on the intended end use of the hydroentangled nonwoven web.

The drape, softness and comfortable hand of the hydroentangled nonwoven web may be controlled by the energy delivered by the high pressure jets and by the speed of travel of the web through the equipment. According to the present invention by control of both water pressure and speed of travel through the spunlacing equipment as well as the absence of adhesives, binders or bonding fibers, a nonwoven web of the mechanically entangled or consolidated defribrated natural cellulose fibers and regenerated cellulosic fibers having varying degrees of high strength, rapid dispersibility or disintegration, absorbency, softness and thickness may be obtained.

Spunlacing or hydroentanglement units are available from Fleissner GmbH. (Germany) and Andritz Perfojet (France).

The mat subjected to the hydroentanglement may be obtained by an air layering method.

FIG. 2 shows a schematic drawing of an embodiment of a continuous system for preparing the hydroentangled nonwoven web wherein the mat is prepared in an airforming system The airforming system is shown as unit (7), wherein the defibrated natural cellulose fibers (1) and regenerated cellulosic fiber (2) are homogeneously mixed in supply unit (3) and then transferred into rotating cylinder (4) having perforations (5). The mixture of defibrated natural cellulose fibers and staple fibers pass through the perforations onto the foraminous carrier (6) which transports the airlaid mat through the hydroentangling unit (8) as described above. From the unit (8) the consolidated nonwoven web is dried in drying unit (9).

In one variation of the above basic embodiment, multiple airlaid mats may be prepared and stacked prior to spunlacing so that thicker nonwoven webs may be produced. The respective stacked layers may be of the same fiber composition or may have differing compositions selected for the intended end use of the nonwoven web. In each such possible embodiment, entanglement may be achieved by variation of water jet pressure and speed of travel of the web through the spunlacing unit. No binders, adhesives or bonding fibers are utilized.

In another embodiment, the mat may be prepared in a conventional wetlaying process wherein the refined natural cellulose fibers and sustainable fibers may be first mechanically mixed in water to form an aqueous dispersion and then applied to a supporting screen or fabric where the water is removed and the homogeneous mat of the refined natural cellulose fibers and sustainable fibers retained. As in the above described embodiments no adhesives, binders or binding fibers may be included in the wet formed mat.

Further consideration of degree of refining of both the natural cellulose fibers and the manmade sustainable fibers may be directed to targeted properties of the hydroentangled nonwoven web. In this regard, the natural cellulose fibers and manmade sustainable fibers may be refined separately and subsequently combined to produce the wetlaid homogeneous web or the two fibers may be refined together in one operation. One of skill recognizes that refining intensity must be adjusted such that the manmade sustainable fibers are not degraded in the process. Lyocell may be particularly useful as a refined or co-refined manmade sustainable fiber as refining results in a fiber of increased surface area.

Following the hydroentangling operation the wet hydroentangled nonwoven web may be dried and wound for transport and storage. In a further embodiment, prior to drying, the entangled web may be embossed either by a hydroembossing process or by thermal embossing.

The nonwoven fibrous composition described in the embodiments above may be employed to produce a wide range of personal hygiene and cleansing products including disposable cleansing wipes, disposable diapers, disposable adult incontinence products, disposable pads typically employed in hospitals for absorption of body fluids and cosmetic applicators or cosmetic pads for removal of make-up and other materials from a keratinous substrate, in highly preferred uses the nonwoven fibrous composition may be constructed as a disposable wipe.

In each of the utilities described the product may contain only biodegradable materials based on sustainable raw materials and containing no adhesives, binders or binding fibers. Further the product may be deemed “flushable” and suitable for direct disposal in municipal sewer systems and private septic systems.

Thus, in further embodiments a flushable personal hygiene product containing the nonwoven hydroentangled web of defribrated natural cellulose fibers and regenerated cellulosic fibers as described above is provided. Additionally, a flushable disposable wipe or flushable cosmetic wipe containing the nonwoven hydroentangled web of defribrated or refined natural cellulose fibers and manmade sustainable fibers as described above is provided. The flushable disposable wipe or cosmetic wipe may contain at least one of a cleansing agent, a sterilizing agent, a deodorizing agent, a disinfectant, a moisturizing agent and a cosmetic remover.

The above description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, certain embodiments within the invention may not show every benefit of the invention, considered broadly.

The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention.

EXAMPLES

Five hydroentangled webs were prepared according to the first embodiment as described previously. The webs are designated as JH1, JH2, JH3, JH4 and JH5. All webs were based on air layered mats which were hydroentangled. JH1 and JH2 were prepared with 1.9 denier and 2.0 denier viscose fiber and are not according to the present invention. JH3, JH4 and JH5 were prepared with viscose fiber of less than 1.0 denier at differing density (Dry Basis Weight−Dry BW). Wet strength and Slosh Box break up time were measured for each of the samples in comparison to commercially available wet wipe products.

The results are shown in the Table of FIG. 3. As indicated each of samples JH3, JH4 and JH5 have significantly faster break-up times while having comparable or greater CD wet strength. For JH3 and JH5, having a dry basis weight between 60 and 70 g/m², the CD wet strengths are unexpectedly greater than any of the other listed samples. This combination of high CD wet strength and rapid break up time is surprising in view of the conventional wisdom that wet strength and break up time must be compromised. 

1. A nonwoven fibrous composition, comprising as a hydroentangled web: from 60 to 90% by weight of defrbrated or refined natural cellulose fibers and from 10 to 40% by weight of manmade sustainable fibers; wherein the nonwoven fibrous hydroentangled web comprises no binder, adhesive or thermal bonding fiber, a fiber length of the defrbrated or refined natural cellulose fibers is less than or equal to 3.5 mm, a fiber length of the manmade sustainable fibers is from 6.0 to 12.0 mm, a denier of the manmade sustainable fibers is 1.0 dpf or less, a basis weight of the nonwoven fibrous web is from 20 g/m² to 100 g/m², and a thickness of the nonwoven web is from 0.25 mm to 2 mm.
 2. The nonwoven fibrous composition of claim 1 wherein a CD wet strength of the hydroentangled web is at least 5N/5 cm.
 3. The nonwoven fibrous composition of claim 2, wherein the CD wet strength is from 5N/5 cm to 9N/5 cm.
 4. The nonwoven fibrous composition of claim 1 wherein a Slosh Box dispersibility time is 15 minutes or less.
 5. The nonwoven fibrous composition of claim 4 wherein the Slosh Box dispersibility time is less than 12 minutes.
 6. The nonwoven fibrous composition of claim 3 wherein the basis weight of the nonwoven fibrous web is from 60 to 70 g/m².
 7. The nonwoven fibrous composition of claim 6, wherein a Slosh Box dispersibility time is less than 12 minutes.
 8. The nonwoven fibrous composition of claim 1 wherein the manmade sustainable fiber is at least one selected from the group consisting of cellulose acetate, polylactic acid, esters of polylactic acid, amides of polylactic acid, lyocell, viscose and milk protein.
 9. The nonwoven fibrous composition of claim 1 wherein the manmade sustainable fiber comprises a viscose, a lyocell or a mixture of a viscose and a lyocell.
 10. A method to prepare the nonwoven fibrous composition of claim 1, comprising: preparing a uniform mat comprising from 60 to 90% by weight of defibrated or refined natural cellulose fibers; and from 10 to 40% by weight of manmade sustainable fibers; hydroentangling the uniform web on a carrier to consolidate the web on at least one side; and drying the hydroentangled web to obtain the nonwoven fibrous composition; wherein no binder, adhesive or thermal bonding fiber is employed.
 11. The method of claim 10, wherein the uniform mat is prepared by an air laying process comprising: preparing a homogeneous mixture of defibrated natural cellulose fibers and manmade sustainable fibers; transferring the prepared homogeneous mixture into a rotating cylinder having perforations; passing the homogenous mixture defibrated natural cellulose fibers and manmade sustainable fibers through the perforations onto a foraminous carrier to form the uniform mat.
 12. The method of claim 11, wherein the process from air laying to hydroentanglement is conducted continuously and the foraminous carrier transports the airlaid mat through the hydroentangling unit.
 13. The method of claim 10, wherein the uniform mat is prepared by a wet laying process, comprising: preparing an aqueous dispersion of the refined natural cellulose fibers and optionally refined manmade sustainable fibers; applying the aqueous dispersion to a supporting screen or fabric; removing the water of the aqueous dispersion; and forming the homogeneous mat of the refined natural cellulose fibers and optionally refined manmade sustainable fibers.
 14. A cleaning wipe, comprising: the nonwoven fibrous composition according to claim 1; wherein the cleaning wipe is deemed flushable for disposal in a municipal sewer system or septic system.
 15. The cleaning wipe of claim 14, further comprising at least one component selected from the group consisting of a cleansing agent, a sterilizing agent, a deodorizing agent, a disinfectant, a moisturizing agent and a cosmetic remover. 